/**
 * @file
 * lwIP network interface abstraction
 *
 */

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

#include "lwip/opt.h"

#include "lwip/def.h"
#include "lwip/ip_addr.h"
#include "lwip/netif.h"
#include "lwip/tcp.h"
#include "lwip/igmp.h"
#include "netif/etharp.h"

#if LWIP_NETIF_STATUS_CALLBACK
#define NETIF_STATUS_CALLBACK(n) { if (n->status_callback) (n->status_callback)(n); }
#else
#define NETIF_STATUS_CALLBACK(n) { /* NOP */ }
#endif /* LWIP_NETIF_STATUS_CALLBACK */

#if LWIP_NETIF_LINK_CALLBACK
#define NETIF_LINK_CALLBACK(n) { if (n->link_callback) (n->link_callback)(n); }
#else
#define NETIF_LINK_CALLBACK(n) { /* NOP */ }
#endif /* LWIP_NETIF_LINK_CALLBACK */

struct netif *netif_list;
struct netif *netif_default;

/**
 * Add a network interface to the list of lwIP netifs.
 *
 * @param netif a pre-allocated netif structure
 * @param ipaddr IP address for the new netif
 * @param netmask network mask for the new netif
 * @param gw default gateway IP address for the new netif
 * @param state opaque data passed to the new netif
 * @param init callback function that initializes the interface
 * @param input callback function that is called to pass
 * ingress packets up in the protocol layer stack.
 *
 * @return netif, or NULL if failed.
 */
struct netif *
netif_add (struct netif *netif, struct ip_addr *ipaddr,
	   struct ip_addr *netmask, struct ip_addr *gw, void *state,
	   err_t (*init) (struct netif * netif),
	   err_t (*input) (struct pbuf * p, struct netif * netif))
{
  static u8_t netifnum = 0;

  /* reset new interface configuration state */
  netif->ip_addr.addr = 0;
  netif->netmask.addr = 0;
  netif->gw.addr = 0;
  netif->flags = 0;
#if LWIP_DHCP
  /* netif not under DHCP control by default */
  netif->dhcp = NULL;
#endif /* LWIP_DHCP */
#if LWIP_AUTOIP
  /* netif not under AutoIP control by default */
  netif->autoip = NULL;
#endif /* LWIP_AUTOIP */
#if LWIP_NETIF_STATUS_CALLBACK
  netif->status_callback = NULL;
#endif /* LWIP_NETIF_STATUS_CALLBACK */
#if LWIP_NETIF_LINK_CALLBACK
  netif->link_callback = NULL;
#endif /* LWIP_NETIF_LINK_CALLBACK */
#if LWIP_IGMP
  netif->igmp_mac_filter = NULL;
#endif /* LWIP_IGMP */

  /* remember netif specific state information data */
  netif->state = state;
  netif->num = netifnum++;
  netif->input = input;
#if LWIP_NETIF_HWADDRHINT
  netif->addr_hint = NULL;
#endif /* LWIP_NETIF_HWADDRHINT */

  netif_set_addr (netif, ipaddr, netmask, gw);

  /* call user specified initialization function for netif */
  if (init (netif) != ERR_OK)
    {
      return NULL;
    }

  /* add this netif to the list */
  netif->next = netif_list;
  netif_list = netif;

#if LWIP_IGMP
  /* start IGMP processing */
  if (netif->flags & NETIF_FLAG_IGMP)
    {
      igmp_start (netif);
    }
#endif /* LWIP_IGMP */

  LWIP_DEBUGF (NETIF_DEBUG, ("netif: added interface %c%c IP addr ",
			     netif->name[0], netif->name[1]));
  ip_addr_debug_print (NETIF_DEBUG, ipaddr);
  LWIP_DEBUGF (NETIF_DEBUG, (" netmask "));
  ip_addr_debug_print (NETIF_DEBUG, netmask);
  LWIP_DEBUGF (NETIF_DEBUG, (" gw "));
  ip_addr_debug_print (NETIF_DEBUG, gw);
  LWIP_DEBUGF (NETIF_DEBUG, ("\n"));
  return netif;
}

/**
 * Change IP address configuration for a network interface (including netmask
 * and default gateway).
 *
 * @param netif the network interface to change
 * @param ipaddr the new IP address
 * @param netmask the new netmask
 * @param gw the new default gateway
 */
void
netif_set_addr (struct netif *netif, struct ip_addr *ipaddr,
		struct ip_addr *netmask, struct ip_addr *gw)
{
  netif_set_ipaddr (netif, ipaddr);
  netif_set_netmask (netif, netmask);
  netif_set_gw (netif, gw);
}

/**
 * Remove a network interface from the list of lwIP netifs.
 *
 * @param netif the network interface to remove
 */
void
netif_remove (struct netif *netif)
{
  if (netif == NULL)
    return;

#if LWIP_IGMP
  /* stop IGMP processing */
  if (netif->flags & NETIF_FLAG_IGMP)
    {
      igmp_stop (netif);
    }
#endif /* LWIP_IGMP */

  /*  is it the first netif? */
  if (netif_list == netif)
      netif_list = netif->next;
  else
    {
      /*  look for netif further down the list */
      struct netif *tmpNetif;
      for (tmpNetif = netif_list; tmpNetif != NULL; tmpNetif = tmpNetif->next)
	{
	  if (tmpNetif->next == netif)
	    {
	      tmpNetif->next = netif->next;
	      break;
	    }
	}
      if (tmpNetif == NULL)
	return;			/*  we didn't find any netif today */
    }
  /* this netif is default? */
  if (netif_default == netif)
    /* reset default netif */
    netif_set_default (NULL);
  LWIP_DEBUGF (NETIF_DEBUG, ("netif_remove: removed netif\n"));
}

/**
 * Find a network interface by searching for its name
 *
 * @param name the name of the netif (like netif->name) plus concatenated number
 * in ascii representation (e.g. 'en0')
 */
struct netif *
netif_find (char *name)
{
  struct netif *netif;
  u8_t num;

  if (name == NULL)
    {
      return NULL;
    }

  num = name[2] - '0';

  for (netif = netif_list; netif != NULL; netif = netif->next)
    {
      if (num == netif->num &&
	  name[0] == netif->name[0] && name[1] == netif->name[1])
	{
	  LWIP_DEBUGF (NETIF_DEBUG,
		       ("netif_find: found %c%c\n", name[0], name[1]));
	  return netif;
	}
    }
  LWIP_DEBUGF (NETIF_DEBUG,
	       ("netif_find: didn't find %c%c\n", name[0], name[1]));
  return NULL;
}

/**
 * Change the IP address of a network interface
 *
 * @param netif the network interface to change
 * @param ipaddr the new IP address
 *
 * @note call netif_set_addr() if you also want to change netmask and
 * default gateway
 */
void
netif_set_ipaddr (struct netif *netif, struct ip_addr *ipaddr)
{
  /* TODO: Handling of obsolete pcbs */
  /* See:  http://mail.gnu.org/archive/html/lwip-users/2003-03/msg00118.html */
#if LWIP_TCP
  struct tcp_pcb *pcb;
  struct tcp_pcb_listen *lpcb;

  /* address is actually being changed? */
  if ((ip_addr_cmp (ipaddr, &(netif->ip_addr))) == 0)
    {
      /* extern struct tcp_pcb *tcp_active_pcbs; defined by tcp.h */
      LWIP_DEBUGF (NETIF_DEBUG | 1,
		   ("netif_set_ipaddr: netif address being changed\n"));
      pcb = tcp_active_pcbs;
      while (pcb != NULL)
	{
	  /* PCB bound to current local interface address? */
	  if (ip_addr_cmp (&(pcb->local_ip), &(netif->ip_addr)))
	    {
	      /* this connection must be aborted */
	      struct tcp_pcb *next = pcb->next;
	      LWIP_DEBUGF (NETIF_DEBUG | 1,
			   ("netif_set_ipaddr: aborting TCP pcb %p\n",
			    (void *) pcb));
	      tcp_abort (pcb);
	      pcb = next;
	    }
	  else
	    {
	      pcb = pcb->next;
	    }
	}
      for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL;
	   lpcb = lpcb->next)
	{
	  /* PCB bound to current local interface address? */
	  if ((!(ip_addr_isany (&(lpcb->local_ip)))) &&
	      (ip_addr_cmp (&(lpcb->local_ip), &(netif->ip_addr))))
	    {
	      /* The PCB is listening to the old ipaddr and
	       * is set to listen to the new one instead */
	      ip_addr_set (&(lpcb->local_ip), ipaddr);
	    }
	}
    }
#endif
  /* set new IP address to netif */
  ip_addr_set (&(netif->ip_addr), ipaddr);

  LWIP_DEBUGF (NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 3,
	       ("netif: IP address of interface %c%c set to %" U16_F ".%"
		U16_F ".%" U16_F ".%" U16_F "\n", netif->name[0],
		netif->name[1], ip4_addr1 (&netif->ip_addr),
		ip4_addr2 (&netif->ip_addr), ip4_addr3 (&netif->ip_addr),
		ip4_addr4 (&netif->ip_addr)));
}

/**
 * Change the default gateway for a network interface
 *
 * @param netif the network interface to change
 * @param gw the new default gateway
 *
 * @note call netif_set_addr() if you also want to change ip address and netmask
 */
void
netif_set_gw (struct netif *netif, struct ip_addr *gw)
{
  ip_addr_set (&(netif->gw), gw);
  LWIP_DEBUGF (NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 3,
	       ("netif: GW address of interface %c%c set to %" U16_F ".%"
		U16_F ".%" U16_F ".%" U16_F "\n", netif->name[0],
		netif->name[1], ip4_addr1 (&netif->gw),
		ip4_addr2 (&netif->gw), ip4_addr3 (&netif->gw),
		ip4_addr4 (&netif->gw)));
}

/**
 * Change the netmask of a network interface
 *
 * @param netif the network interface to change
 * @param netmask the new netmask
 *
 * @note call netif_set_addr() if you also want to change ip address and
 * default gateway
 */
void
netif_set_netmask (struct netif *netif, struct ip_addr *netmask)
{
  /* set new netmask to netif */
  ip_addr_set (&(netif->netmask), netmask);
  LWIP_DEBUGF (NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 3,
	       ("netif: netmask of interface %c%c set to %" U16_F ".%" U16_F
		".%" U16_F ".%" U16_F "\n", netif->name[0], netif->name[1],
		ip4_addr1 (&netif->netmask), ip4_addr2 (&netif->netmask),
		ip4_addr3 (&netif->netmask), ip4_addr4 (&netif->netmask)));
}

/**
 * Set a network interface as the default network interface
 * (used to output all packets for which no specific route is found)
 *
 * @param netif the default network interface
 */
void
netif_set_default (struct netif *netif)
{
  netif_default = netif;
  LWIP_DEBUGF (NETIF_DEBUG, ("netif: setting default interface %c%c\n",
			     netif ? netif->name[0] : '\'',
			     netif ? netif->name[1] : '\''));
}

/**
 * Bring an interface up, available for processing
 * traffic.
 * 
 * @note: Enabling DHCP on a down interface will make it come
 * up once configured.
 * 
 * @see dhcp_start()
 */
void
netif_set_up (struct netif *netif)
{
  if (!(netif->flags & NETIF_FLAG_UP))
    {
      netif->flags |= NETIF_FLAG_UP;

      NETIF_LINK_CALLBACK (netif);
      NETIF_STATUS_CALLBACK (netif);

#if LWIP_ARP
    /** For Ethernet network interfaces, we would like to send a
     *  "gratuitous ARP"; this is an ARP packet sent by a node in order
     *  to spontaneously cause other nodes to update an entry in their
     *  ARP cache. From RFC 3220 "IP Mobility Support for IPv4" section 4.6.
     */
      if (netif->flags & NETIF_FLAG_ETHARP)
	{
	  etharp_query (netif, &(netif->ip_addr), NULL);
	}
#endif /* LWIP_ARP */

    }
}

/**
 * Bring an interface down, disabling any traffic processing.
 *
 * @note: Enabling DHCP on a down interface will make it come
 * up once configured.
 * 
 * @see dhcp_start()
 */
void
netif_set_down (struct netif *netif)
{
  if (netif->flags & NETIF_FLAG_UP)
    {
      netif->flags &= ~NETIF_FLAG_UP;

      NETIF_LINK_CALLBACK (netif);
      NETIF_STATUS_CALLBACK (netif);
    }
}

/**
 * Ask if an interface is up
 */
u8_t
netif_is_up (struct netif *netif)
{
  return (netif->flags & NETIF_FLAG_UP) ? 1 : 0;
}

#if LWIP_NETIF_STATUS_CALLBACK
/**
 * Set callback to be called when interface is brought up/down
 */
void
netif_set_status_callback (struct netif *netif,
			   void (*status_callback) (struct netif * netif))
{
  if (netif)
    netif->status_callback = status_callback;
}
#endif /* LWIP_NETIF_STATUS_CALLBACK */

#if LWIP_NETIF_LINK_CALLBACK
/**
 * Called by a driver when its link goes up
 */
void
netif_set_link_up (struct netif *netif)
{
  netif->flags |= NETIF_FLAG_LINK_UP;

#if LWIP_ARP
  /** For Ethernet network interfaces, we would like to send a
   *  "gratuitous ARP"; this is an ARP packet sent by a node in order
   *  to spontaneously cause other nodes to update an entry in their
   *  ARP cache. From RFC 3220 "IP Mobility Support for IPv4" section 4.6.
   */
  if (netif->flags & NETIF_FLAG_ETHARP)
    {
      etharp_query (netif, &(netif->ip_addr), NULL);
    }
#endif /* LWIP_ARP */

#if LWIP_IGMP
  /* resend IGMP memberships */
  if (netif->flags & NETIF_FLAG_IGMP)
    {
      igmp_report_groups (netif);
    }
#endif /* LWIP_IGMP */

  NETIF_LINK_CALLBACK (netif);
}

/**
 * Called by a driver when its link goes down
 */
void
netif_set_link_down (struct netif *netif)
{
  netif->flags &= ~NETIF_FLAG_LINK_UP;
  NETIF_LINK_CALLBACK (netif);
}

/**
 * Ask if a link is up
 */
u8_t
netif_is_link_up (struct netif *netif)
{
  return (netif->flags & NETIF_FLAG_LINK_UP) ? 1 : 0;
}

/**
 * Set callback to be called when link is brought up/down
 */
void
netif_set_link_callback (struct netif *netif,
			 void (*link_callback) (struct netif * netif))
{
  if (netif)
    netif->link_callback = link_callback;
}
#endif /* LWIP_NETIF_LINK_CALLBACK */
